A large literature examines the effect of health insurance on mortality. We contribute by emphasizing two challenges in using the Affordable Care Act (ACA)’s quasi-experimental variation to study mortality. The first is non-parallel pretreatment trends. Rising mortality in Medicaid non-expansion relative to expansion states prior to Medicaid expansion makes it difficult to estimate the effect of insurance using difference-in-differences (DD). We use various DD, triple difference, age-discontinuity and synthetic control approaches, but are unable to satisfactorily address this concern. Our estimates are not statistically significant, but are imprecise enough to be consistent with both no effect and a large effect of insurance on amenable mortality over the first three post-ACA years. Thus, ...